java - DateTimeFormatter.ISO_INSTANT 毫秒级问题

Question

我正在使用 DateTimeFormatter，但在 999 毫秒后的毫秒结束时，它会丢失毫秒字段。如果 java 存在此问题，请告诉我

public static void main(String[] args) throws IOException {
            // TODO Auto-generated method stub
            File file = new File("/users/test/filenamedate12.txt");

            // if file doesnt exists, then create it
            if (!file.exists()) {
                file.createNewFile();
            }
            BufferedWriter bw= null;
            FileWriter fw = new FileWriter(file.getAbsoluteFile());
            bw = new BufferedWriter(fw);
            for(int i=0;i<=1000000;i++){
            ZonedDateTime zdt = ZonedDateTime.now();
            String  content =zdt.format(DateTimeFormatter.ISO_INSTANT);


                //String content = "This is the content to write into create file";


            bw.write(content);
             bw.newLine();



            }

            bw.flush();
            bw.close();
        }

输出样本

2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:56.999Z
2016-04-05T22:32:57Z
2016-04-05T22:32:57Z
2016-04-05T22:32:57Z
2016-04-05T22:32:57Z
2016-04-05T22:32:57Z
2016-04-05T22:32:57Z
2016-04-05T22:32:57Z
2016-04-05T22:32:57Z

Answer 1

不，这是故意的。来自 DateTimeFormatter.ISO_INSTANT 的 javadoc:

The nano-of-second outputs zero, three, six or nine digits digits as necessary.

换句话说，为了简洁起见，删除了 . 之后的冗余 0。

源代码显示:

ISO_INSTANT = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .appendInstant()
                .toFormatter(ResolverStyle.STRICT, null);

appendInstant 方法负责此行为。该方法的文档也提到了它。